The Descent of Man

ates,' vol. iii. p. 619.) than those on the lowlands.
May we then infer that man became divested
of hair from having aboriginally inhabited
some tropical land? That the hair is chiefly
retained in the male sex on the chest and face,
and in both sexes at the junction of all four
limbs with the trunk, favours this inference—
on the assumption that the hair was lost before
man became erect; for the parts which now
retain most hair would then have been most
protected from the heat of the sun. The crown
of the head, however, offers a curious exception,
for at all times it must have been one of
the most exposed parts, yet it is thickly clothed
with hair. The fact, however, that the other
members of the order of Primates, to which
man belongs, although inhabiting various hot
regions, are well clothed with hair, generally
thickest on the upper surface (88. Isidore Geoffroy
St.-Hilaire remarks ('Histoire Nat. Generale,'
tom. ii. 1859, pp. 215-217) on the head of
man being covered with long hair; also on the